CN109804143B

CN109804143B - Sheet metal locking cover for cam phaser

Info

Publication number: CN109804143B
Application number: CN201780062700.5A
Authority: CN
Inventors: 雷纳托·德奥利韦拉吉拉尔迪; 亚历山大·卡米洛
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2016-10-28
Filing date: 2017-10-09
Publication date: 2021-03-12
Anticipated expiration: 2037-10-09
Also published as: US20180119581A1; DE112017005464T5; CN109804143A; US10167747B2; WO2018080776A1

Abstract

A cam phaser comprising: a stator; a rotor positioned in the stator; a cover plate positioned on a first side of the stator; a locking cover positioned on a second side of the stator; a locking pin assembly configured to selectively lock the rotor in position relative to the stator; a plurality of aligned first openings extending through the stator, cover plate and locking cover; a plurality of fasteners inserted into the plurality of aligned first openings, respectively; and a plurality of aligned central openings forming a through-hole. The locking cover has a body made of sheet metal having a first axial side, a second axial side, a plurality of first openings, and a second opening. The body has a web portion and a plurality of reinforcing portions that are thicker than the web portion.

Description

Sheet metal locking cover for cam phaser

Cross Reference to Related Applications

This application claims the benefit of U.S. patent application No. 15/338,309 filed on 28/10/2016, which is incorporated by reference as if fully set forth herein.

Technical Field

The present invention relates to a cam phaser and, more particularly, to a sheet metal locking cover for a cam phaser.

Background

Cam phasers are known devices used in engines to change valve timing. Many cam phasers, such as vane cam phasers, include a locking cover attached outside of the moving parts of the phaser. The locking cover may serve as a stationary component that helps to retain the rotor in the stator and facilitates locking of the locking pins.

Fig. 3A and 3B illustrate an example of a prior art locking cap 100 that may be used in conjunction with a cam phaser. The locking cap 100 is annular and includes a body 102 of uniform thickness, the body 102 having a central aperture 104 extending therethrough. The locking cap 100 also includes a plurality of through holes 106, the plurality of through holes 106 receiving fasteners for retaining the locking cap 100 to a stator (not shown) of a cam phaser. The locking cap 100 also includes a second through-hole 108, the second through-hole 108 receiving a bushing 110. The bushing 110 is cup-shaped so as to form a space 112 for receiving a locking pin therein.

Current manufacturing methods commonly employed to form locking cap 100 include molding and fine blanking using powdered metal. However, these processes use a relatively large amount of raw materials to produce the locking cap 100. In turn, cam phasers using known locking covers 100 are large and heavy, and have high manufacturing costs due in part to the construction of the locking cover. Attempting to solve some of these problems by simply sizing the uniform thickness of the locking cap 100 is not a suitable solution as it would reduce the strength of the locking cap and make the locking cap 100 more susceptible to cracking or other types of deformation. Furthermore, a uniformly thinner locking cap would not match the thickness of the existing bushing 110.

The present disclosure is directed to solving one or more problems of the prior art.

Disclosure of Invention

In one aspect, the present disclosure is directed to a cam phaser. The cam phaser includes: a stator; a rotor positioned in the stator; a cover plate positioned at a first side of the stator; a locking cover positioned at a second side of the stator; a locking pin assembly configured to selectively lock the rotor in position relative to the stator; a plurality of aligned first openings extending through the stator, the cover plate and the locking cover; a plurality of fasteners inserted into the plurality of aligned first openings, respectively; and a plurality of aligned central openings forming a through-hole. The locking cover includes a body formed of sheet metal, the body having: a first axial side; a second axial side; a plurality of first openings extending from a first axial side to a second axial side; and a second opening extending from the first axial side to the second axial side. The body includes a web portion and a plurality of reinforcement portions that are thicker than the web portion.

In another aspect, the present disclosure is directed to a method of manufacturing a cam phaser. The cam phaser includes a stator, a rotor, a cover plate, a locking cap, a locking pin assembly, and a plurality of fasteners. The method comprises the following steps: deep drawing a sheet metal blank to produce a locking lid comprising a body including a web portion and a plurality of reinforcement portions, the plurality of reinforcement portions being thicker than the web portion; and stamping the blank to create a plurality of first openings, a central opening, and a second opening. The method further includes assembling a cam phaser, comprising: positioning the bushing in the second opening; positioning a locking cap adjacent to the stator; and inserting a plurality of fasteners through aligned openings in the cover plate, the stator, and the locking cover, the aligned openings including the plurality of first openings.

Drawings

The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings, which illustrate preferred embodiments of the invention. In the drawings:

fig. 1 is a cross-sectional view of a cam phaser including a locking cover according to an embodiment of the present invention;

FIG. 2A is a perspective view of the locking cap of FIG. 1;

FIG. 2B is a cross-sectional view of the locking cap of FIG. 1;

FIG. 3A is a perspective view of a prior art locking cover; and is

Fig. 3B is a cross-sectional view of the locking cap of fig. 3A.

Detailed Description

Fig. 1 illustrates an exemplary cam phaser 10. The cam phaser 10 is preferably used in conjunction with an engine, such as an internal combustion engine, to vary valve timing in a manner known in the art (e.g., via hydraulic pressure). For example, the cam phaser 10 may be a vane cell cam phaser. The cam phaser 10 preferably includes at least a stator 12, a rotor 14, a cover plate 16, a lock cover 18, a lock pin assembly 20, and a plurality of fasteners 22. Depending on the application, the cam phaser 10 may include additional components not described herein. For example, some configurations may include components such as solenoids, torsion springs, housing components, cam members, shafts, and the like.

The rotor 14 is positioned within the stator 12 and rotates within the stator 12 (e.g., via hydraulic pressure) to vary valve timing in a manner known in the art. For example, a plurality of hydraulic chambers (not shown) may be formed between the rotor 14 and the vanes of the stator 12, wherein varying hydraulic pressure in the hydraulic chambers causes the rotor 14 to move within the stator 12. A cover plate 16 is positioned on one side of the stator 12 and rotor 14 and a locking cover 18 is positioned on the opposite side of the stator 12 and rotor 14. The stator 12, cover plate 16, and locking cover 18 preferably each include a plurality of first openings 24 for receiving fasteners 22 (e.g., bolts) when respectively aligned with one another. The rotor 14, cover plate 16 and locking cover 18 preferably each include a central opening 26. The locking cover 18 includes a second opening 28, the second opening 28 for receiving a portion of the locking pin assembly 20, as will be described in further detail below.

Locking pin assembly 20 includes a pin 30, a spring 32, a movable locking member 36, and a bushing 38. The pin 30 is preferably attached to the rotor 14 and is movable with the rotor 14. A movable locking member 36 is positioned on the end of pin 30 and is slidable on pin 30 and is biased to an extended position by spring 32. Under certain conditions (e.g., hydraulic pressure above or below a threshold level), the movable locking member 36 is biased by the spring 32 into the cup-shaped bushing 38. Receipt of the movable lock 36 in the bushing 38 locks the rotor 14 into a particular position relative to the stator 12 until the locking pin assembly 20 is unlocked due to an increase in hydraulic pressure.

Fig. 2A-2B further illustrate the locking cover 18. The locking cap 18 includes a body 40 formed of sheet metal, the body 40 having a first axial side 42 and a second axial side 44. The first opening 24 is positioned around the body 40 and extends from a first axial side 42 to a second axial side 44. The central opening 26 of the locking cap 18 extends through the center of the body 40. The second opening 28 is formed in place and extends from the first axial side 42 to the second axial side 44, and the second opening 28 receives the bushing 38 therein.

The locking cover 18 is formed of sheet metal and is thinner than prior art locking plates, such as the locking cover 100 of fig. 3A-3B, the locking cover 18 including the web portion 46. To provide additional strength and rigidity to the locking plate 100, some areas of the body 40 are thicker than most of the locking plate 100. These areas are referred to herein as reinforcements. For example, the locking cover 18 may include a rim 48 extending around the perimeter of the body 40. Additionally, the locking cover 18 may also include

bosses

50, 52, the

bosses

50, 52 completely surrounding the first and

second openings

24, 28, respectively. These reinforcements provide increased stiffness to the areas (e.g., at the edges) that may be most susceptible to deformation or rupture.

In the illustrated embodiment, the reinforcement is provided on only one side (e.g., the first axial side 42) of the locking cap 18. In this manner, the second axial side 44 is flat (i.e., planar) over the entire side of the body 40 so that the locking cap 18 can be placed flat against the stator 12 and rotor 14 (see fig. 1). In other embodiments, the reinforcement may be formed on both the first and second

axial sides

42, 44 or only the second axial side 44.

As shown in fig. 1 and 2B, the locking cap 18 and boss 52 may be sized to match the size of the bushing 38. In other words, when the bushing 38 is in the second opening 28, the open end of the bushing is flush with the body 40 on the second axial side 44 and the closed end of the bushing is flush with the body 40 (e.g., the rim of the boss 52) on the first axial side 42.

The exemplary disclosed locking cover 18 is preferably manufactured using a deep drawing and/or stamping process. In an exemplary disclosed process, a thin sheet metal blank is deep drawn to form the reinforcements (e.g., rim 46 and bosses 50, 52). A stamping step is also performed to form the first opening 24, the central opening 26 and the second opening 28. This process results in a locking cover 18 that is significantly thinner than previous locking covers (e.g., locking cover 100) while maintaining the strength and rigidity necessary to withstand the forces associated with the operation of the cam phaser 10.

In another process, the locking cap 18 is assembled with the cam phaser 10. The process may include: positioning the bushing 38 in the second opening 28; aligning the locking cap 18 with the rotor 14; and inserting the fastener 22 through the first opening 24. During operation, the bushing 38 is positioned such that the movable lock 36 can be inserted into the bushing 38 to selectively lock the rotor 14 via the lock pin assembly 20.

Thus, the disclosed locking cover 18 provides a thinner component that uses less raw material (reduces cost), has less mass, takes up less space, and can be manufactured by a more efficient process than previous locking covers.

Having thus described in detail the presently preferred embodiments, it is to be understood and will be apparent to those skilled in the art that numerous physical changes may be made without departing from the inventive concepts and principles embodied in the present invention, only some of which are illustrated in the detailed description of the invention. It should also be appreciated that many embodiments are possible which incorporate only a portion of the preferred embodiments which do not alter the inventive concepts and principles embodied therein to those portions. The present embodiments and alternative constructions are therefore to be considered in all respects as illustrative and/or illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all alternative embodiments and modifications to the embodiments that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Parts list

10. Cam phaser

12. Stator

14. Rotor

16. Cover plate

18. Locking cover

20. Locking pin assembly

22. Fastening piece

24. First opening

26. Center opening

28. Second opening

30. Pin

32. Spring

34. Bearing assembly

36. Movable cover

38. Bushing

40. Body

42. First axial side

44. Second axial side

46. Web part

48. Edge

50. Boss

52. Boss

100. Locking cover

102. Body

104. Through hole

106. Through hole

108. Second through hole

110. Bushing

Claims

1. A cam phaser, comprising:

a stator;

a rotor positioned in the stator;

a cover plate positioned on a first side of the stator;

a locking cover positioned on a second side of the stator;

a locking pin assembly configured to selectively lock the rotor in position relative to the stator;

a plurality of aligned first openings extending through the stator, the cover plate, and the locking cover;

a plurality of fasteners inserted into the plurality of aligned first openings, respectively; and

a plurality of aligned central openings forming a via,

wherein the locking cover comprises a body made of sheet metal, the body having: a first axial side; a second axial side; a plurality of first openings extending from the first axial side to the second axial side; and a second opening extending from the first axial side to the second axial side, and

wherein, the body includes web portion and a plurality of rib, a plurality of rib than web portion is thick, the rib includes the boss, the boss encircles the second opening.

2. The cam phaser of claim 1, wherein the reinforcement includes a rim extending around a perimeter of the body.

3. The cam phaser of claim 1, wherein the reinforcement includes a plurality of bosses surrounding the plurality of first openings in the lock cover, respectively.

4. The cam phaser of claim 1, wherein the locking pin assembly comprises a pin, a spring, a movable lock, and a bushing, and the bushing is positioned in the second opening of the locking cover.

5. The cam phaser of claim 4, wherein the bushing includes an open end and a closed end, the closed end being flush with the rim of the boss on the first axial side and the open end being flush with the body on the second axial side.

6. The cam phaser of claim 1, wherein the first axial side includes the reinforcement and the second axial side is planar.

7. The cam phaser of claim 4, wherein a thickness of the bushing from the open end to the closed end is greater than a thickness of the web portion.

8. The cam phaser of claim 7, wherein the thickness of the bushing is equal to a thickness of the reinforcement.

9. A method of manufacturing a cam phaser including a stator, a rotor, a cover plate, a locking cap, a locking pin assembly, and a plurality of fasteners, the method comprising:

deep drawing a sheet metal blank to produce the locking lid, the locking lid comprising a body including a web portion and a plurality of reinforcement portions, the plurality of reinforcement portions being thicker than the web portion;

stamping the blank to create a plurality of first openings, a central opening, and a second opening; the reinforcement portion includes a boss surrounding the second opening; and

assembling the cam phaser, comprising:

positioning a bushing in the locking pin assembly in the second opening,

positioning the locking cap adjacent to the stator, an

Inserting the plurality of fasteners through aligned openings in the cover plate, the stator, and the locking cover, the aligned openings including the plurality of first openings.